In certain surgical procedures, e.g., cardiac catheterization, a patient lying on an operating table carried on a platform fixedly mounted on a floor is irradiated by x-rays for prolonged intervals. During the procedure, the patient is moved relative to a source of the x-rays by providing the table with motors and a linkage that move the table and patient relative to the platform in a plane parallel to the floor. At other times, it is essential that the table and patient remain stationary, a result achieved by providing the table with a braking arrangement for holding the table in situ relative to the platform.
A manually controlled switch is electrically connected to the motor and braking mechanism. When the switch is activated to a first state, during which the surgeon does not press a button of the switch, the table is locked by the brake arrangement. When the switch is activated to a second state, while the surgeon presses the button, the table can be moved as desired by the surgeon, merely by the surgeon pushing or pulling a handle that is fixedly mounted on the table and which carries the button. When the button is pushed, the motor for driving the table is activated so that the surgeon need only exert a minimum amount of force on the handle to move the table to the desired position.
The x-ray source can be activated to different intensity levels. The x-ray source is activated to a high intensity level, referred to as the cine mode, to provide an intensity sufficient to expose cine film and to provide fluoroscopy. The x-ray source is activated to a lower intensity, referred to as the fluoroscopy mode, when only fluoroscopy and no exposure of cine film is required. Typically, there is approximately a 4:1 ratio between the intensity level of the cine and fluoroscopy modes. It is frequently necessary for the surgeon to move the table by exerting forces to the table with the handle during cine mode operation of the x-ray source.
Because the surgeon basically stands next to the operating table, he is constantly exposed to x-rays back-scattered from the patient and/or table. The accumulated effect of the back-scattered radiation over many years of conducting surgical procedures may have deleterious effects on the health of the surgeon, and may induce cancer. In an attempt to reduce the x-ray exposure to a surgeon standing next to the side of an operating table while an x-ray source is irradiating a patient, the surgeon usually wears leaded eyeglasses, a lead thyroid covering and a lead apron which covers the chest, abdomen and thighs but leaves uncovered the arms, hands, legs below the knees and head. The radiation protection is only partially effective in blocking radiation and leaves parts of the body uncovered. Switches to control whether the x-ray source is to be operated in the cine mode or fluoroscopy mode are included in foot control pedals located on the floor. The amount of back-scattered x-ray radiation incident on the surgeon, particularly during the cine mode, is believed to be substantial enough to cause damage to the surgeon over a prolonged time period.
It is, accordingly, an object of the present invention to provide a new and improved structure particularly adapted to reduce the amount of x-rays incident on an operator performing a surgical procedure on a patient who is being irradiated by x-rays during the surgical procedure.
Another object of the present invention is to provide a new and improved structure for enabling a surgeon to keep all of his body parts, including his arm and hand, behind an x-ray shield while performing a surgical procedure during which a patient is irradiated with x-rays and for enabling the surgeon to apply forces to an operating table to move the table relative to a source of the x-rays while activating a button for controlling a motor for enabling the table to be driven by the manual forces.
A further object of the invention is to provide a new and improved method of performing a surgical procedure on a patient lying on an operating table so that the amount of x-ray radiation back-scattered from the patient and the table to the surgeon is substantially reduced, particularly during the cine mode of operating a source of the x-rays.
A further object of the invention is to provide a new and improved method of performing a surgical procedure on a patient lying on an operating table to substantially reduce the amount of x-ray radiation back-scattered to the hand and arm of a surgeon manipulating a handle and a switch which enables a motor to be activated to drive the table in response to forces imparted by the surgeon to the handle.